Extendable spool

ABSTRACT

An extendable spool is disclosed. The length of the extendable spool is able to continuously varied. The extendable spool accounts for length variances in flow lines by extending the flow line rather than redirecting the flow. Because the flow direction does not make any turns, erosion is minimized on both the extendable spool and downstream parts. The extendable spool is readily scalable from small diameters to large diameters. Because of this, it requires fewer lines and therefore less setup time to account for length differences between large diameter lines.

TECHNICAL FIELD

The present disclosure relates generally to oil or gas wellboreequipment, and, more particularly, to an extendable spool connector.

BACKGROUND

Accounting for length variances on non-permanent, pressurized,fluid-flow lines is normally accomplished by redirecting the flowthrough one or more turns until the desired length is achieved. Examplesof the traditional length make-up methods are seen with hoses (via theirflexible nature) and swiveling elbows (e.g., Chiksans). However, flowredirection through elbows or hoses accelerates erosion, especially whenthere are particulates in the fluid and/or when the fluid is flowing ata high rate, as seen during hydraulic fracturing operations. Erosion isaccelerated not only on the parts redirecting the flow, but also onparts downstream.

Another drawback of using flow redirection for length make-up is thatthe method is not easily scalable to larger diameters—the required wallthicknesses quickly make installation difficult at best, to impracticalat worst; therefore, traditional flow redirection lines used to make upfor length variances are, relatively speaking, smaller diameters. Onedrawback of only being able to redirect flow with small diameter linesis that multiple redirected-flow lines must be used to account forlength differences between large diameter lines. Therefore, what isneeded is an apparatus, system, or method that addresses one or more ofthe foregoing issues, among one or more other issues.

SUMMARY OF THE INVENTION

The extendable spool accounts for length variances by extending the flowline rather than redirecting the flow. Because the flow direction doesnot make any turns, erosion is minimized on both the extendable spooland downstream parts. The extendable spool is readily scalable fromsmall diameters to large diameters. Because of this, it requires fewerlines and therefore less setup time to account for length differencesbetween large diameter lines.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure will be understood morefully from the detailed description given below and from theaccompanying drawings of various embodiments of the disclosure. In thedrawings, like reference numbers may indicate identical or functionallysimilar elements.

FIG. 1 is a side view of an embodiment of an extendable spool in itsfully contracted position.

FIG. 2 is a side view of the embodiment of FIG. 1 in its fully extendedposition.

FIG. 3 is an isometric cutaway view of the embodiment of FIG. 1 in itsfully contracted position.

FIG. 4 is an isometric cutaway view of the embodiment of FIG. 1 in itsfully extended position.

FIG. 5 is an isometric view of the embodiment of FIG. 1 in its fullyextended position.

FIG. 6 is an alternative embodiment of an extendable spool.

DETAILED DESCRIPTION

In an exemplary embodiment, FIGS. 1 and 2 schematically illustrate anextendable spool 100. The extendable spool 100 is a flow spool with avariable length. FIG. 1 illustrates the extendable spool 100 in fullycontracted or compressed configuration, and FIG. 2 illustrates it in itsfully extended configuration. The length is able to be variedcontinuously, rather than discretely, between the fully contracted andfully extended configurations. FIGS. 3 and 4 show isometric cutawayviews of an embodiment of an extendable spool in fully contracted andfully extended positions.

The structure for two tubular sections of the extendable spool 100through which fluid flows are described first. These sections are thethreaded tube 101 and the inner tube 102. Each tubular section isdesigned to withstand pressurized fluids that may be used in hydraulicfracturing or other high-pressure downhole operations. The threaded tube101 may have an inner diameter, referenced in FIG. 1 as ‘A,’ that isequivalent to the inner diameter of other tubular equipment to which theextendable spool may be connected. The threaded tube 101 may comprise aninner beveled shoulder 120 at which point the inner diameter of thethreaded tube 101 increases from ‘A’ to a larger diameter ‘B.’ Thisincreased diameter ‘B’ of the threaded tube 101 allows it to accommodatethe outer diameter of inner tube 102. The inner surface of the threadedtube 101 and the outer surface of inner tube 102 are both smooth, suchthat the inner tube 102 is able to freely move axially within theincreased inner diameter of the threaded tube 101. If inner tube 102 hasan inner diameter of ‘A,’ then increased inner diameter ‘B’ of thethreaded tube 101 will be substantially similar to diameter ‘A’ plustwice the wall thickness of inner tube 102.

The inner beveled shoulder 120 of the threaded tube 101 may act as aphysical stop to the inward axial movement of inner tube 102 when innertube 102 is axially moved relative to threaded tube 101. The inner tube102 comprises an outer shoulder 130 which similarly may act a physicalstop to the inward axial movement of inner tube 102 relative to threadedtube 101. The inner end portion of inner tube 102 may include a beveledend cap called a wash cone 107 which may be threadably engaged withinner tube 102. In an embodiment, the wash cone 107 may be integral toinner tube 102. The wash cone 107 has an outer diameter that is equal tothe outer diameter of the inner tube 102, and the inner diameter of thewash cone 107 varies radially along the bevel from the inner diameter ofthe inner tube 102 to the increased inner diameter of the threaded tube101.

In the embodiment above, both the inner beveled shoulder 120 of thethreaded tube 101 and the beveled surface of wash cone 107 areconfigured to gradually change their inner diameter from ‘A’ to ‘B.’Accordingly, there are no abrupt interior edges along the flow paththrough the threaded tube 101 and the inner tube 102, even when thethreaded tube 101 and inner tube 102 are configured to different axiallengths of the extendable spool 100.

The ends of the threaded tube 101 and the inner tube 102 may eachthreadably engage with a spool flange 103, which enables both ends ofthe extendable spool 100 to be connected to other tubular equipment. Inan embodiment, the spool flanges may be integral to the threaded tube101 and the inner tube 102.

Sealing between the threaded tube 101 and the inner tube 102 isaccomplished via seals 113, such as o-rings, that sit in grooves on theouter surface of the inner tube 102. Similarly, the wash cone 107 mayaccommodate one or more seals 113 in grooves on its outer surface. Theseals 113 mate with a corrosion resistant sealing surface on the innersurface of the threaded tube 101. Bronze pieces 109, 110, and 111 may beused to facilitate sliding between the different steel parts.

The structure for setting and fixing the length of the extendable spool100 is now described. As noted above, the threaded tube 101 and theinner tube 102 are movable relative to each other. They may be fixedrelative to each other using other components, including tensile tube104, inner wing 105, and outer wing 106. Referring still to FIGS. 1 and2, the threaded tube 101 includes a threaded outer surface with whichthe inner wing 105 is threadably engaged. The axial location of theinner wing 105 along the threaded outer surface of the threaded tube 101serves to define the length of extendable spool 100 and the position ofthe tensile tube 104, as will be described further below.

Still referring to FIGS. 1 and 2, the tensile tube 104 may be threadablyengaged with inner tube 102 at or around the outer shoulder 130 of innertube 102. Aside from the inner threaded connection that tensile tube 104uses to connect to the outer shoulder 130 of inner tube 102, the innersurface of tensile tube 104 is smooth and not threaded. This allows theinner tube 102 and the tensile tube 104 together to freely move axiallywith respect to threaded tube 101 even though the outer surface ofthreaded tube 101 is threaded. The inner tube 102 and the tensile tube104 are axially positioned such that the tensile tube 104 abuts theinner wing 105. As shown in FIGS. 1 and 2, the inner wing 105 and thetensile tube 104 abut at beveled ends, which allows the inner wing 105to have a longer thread on its outer surface. In another embodiment, theinner wing 105 and the tensile tube 104 abut at straight ends.

Tensile tube 104 is fixed in place by outer wing 106, which threadablyengages with the threaded outer surface of inner wing 105, and whichlocks the position of tensile tube 104 by engaging with a matingshoulder 140 of tensile tube 104.

To change the length of the extendable spool 100, the inner wing 105 andouter wing 106 are unscrewed from each other, which allows outer wing106 and tensile tube 104 to axially move relative to each other, andalso allows tensile tube 104 and inner tube 102 to move relative tothreaded tube 101. To extend the length of the spool 100, hydrauliccylinders (shown as element 150 in FIG. 5) can be used to stroke theextendable spool 100 to a desired length by longitudinally moving thetensile tube 104 and the inner tube 102 relative to threaded tube 101.Once the desired length is reached, the inner wing 105 is screwed to thedesired position, or until inner wing 105 abuts tensile tube 104. Inorder to minimize the number of turns required to move inner wing 105into the desired position, the outer surface of threaded tube 101 may beconfigured with multiple-start threads. Once inner wing 105 is in thedesired position, outer wing 106 is screwed back on to inner wing 105 tolock the position of tensile tube 104.

If the operator desires to bring the ends of the spool closer together,the outer wing 106 is unscrewed from the inner wing 105, and the innerwing 105 must be backed away from the tensile tube 104 until inner wing105 reaches the desired position. Then, hydraulic cylinders can retractthe two ends together until the tensile tube 104 makes contact with theinner wing 105 again. The inner and outer wings 105 and 106 are thenscrewed back together to lock the spool 100 at the desired length.

It should be noted that, although tensile tube 104 and inner tube 102are shown as threadably engaged, they may also be connected using pins,bolts, or any other known method of connecting tubular members. The onlyrequirement of the tensile tube is that it remain connected to innertube 102 in order to transfer longitudinal force from one end of thespool to the other and to facilitate adjustment of the length of theextendable spool as described above. As a result, tensile tube 104 andinner tube 102 could be formed as a single piece without departing fromthe scope of the present disclosure.

The threads on the outer surface of threaded tube 101 may be left-hand,or reverse, threads, such that relative counter-clockwise rotation willcause engagement of threaded tube 101 and the inner threads of innerwing 105. The threads that connect the wings (the outer threads of theinner wing 105 and the inner threads of outer wing 106) may beright-hand threads, such that relative clockwise rotation will causeengagement of the outer threads of inner wing 105 and inner threads ofouter wing 106. The combination of right-hand threads at theinner-to-outer wing connection and left-hand threads at theinner-wing-to-threaded tube connection ensures that tightening the wingstightens both ends of the spool together. To accomplish this optionalobjective, the particular orientation of the two threaded portions ofthe inner wing is not important; in other words, it is irrelevant whichset of threads is right-handed and which set of threads is left-handed.What matters is that the orientation of the threads that connect theinner wing to the outer wing is the opposite of the orientation of thethreads that connect the inner wing to the threaded tube. The inner wing105 and outer wing 106 may have radially outwardly extendingprotrusions, or lugs, which facilitate screwing and unscrewing.

FIG. 6 illustrates an alternate embodiment of an extendable spool 200.In this embodiment, the threaded tube 201 maintains a constant innerdiameter ‘A.’ Inner tube 202 has an outer diameter that is substantiallyequal to ‘A’ and an inner diameter ‘C’ that is smaller. Other componentsand aspects of the extendable spool 200 are similar to those describedabove.

It is understood that variations may be made in the foregoing withoutdeparting from the scope of the present disclosure. In several exemplaryembodiments, the elements and teachings of the various illustrativeexemplary embodiments may be combined in whole or in part in some or allof the illustrative exemplary embodiments. In addition, one or more ofthe elements and teachings of the various illustrative exemplaryembodiments may be omitted, at least in part, and/or combined, at leastin part, with one or more of the other elements and teachings of thevarious illustrative embodiments.

Any spatial references, such as, for example, “upper,” “lower,” “above,”“below,” “between,” “bottom,” “vertical,” “horizontal,” “angular,”“upwards,” “downwards,” “side-to-side,” “left-to-right,”“right-to-left,” “top-to-bottom,” “bottom-to-top,” “top,” “bottom,”“bottom-up,” “top-down,” etc., are for the purpose of illustration onlyand do not limit the specific orientation or location of the structuredescribed above.

In several exemplary embodiments, while different steps, processes, andprocedures are described as appearing as distinct acts, one or more ofthe steps, one or more of the processes, and/or one or more of theprocedures may also be performed in different orders, simultaneouslyand/or sequentially. In several exemplary embodiments, the steps,processes, and/or procedures may be merged into one or more steps,processes and/or procedures.

In several exemplary embodiments, one or more of the operational stepsin each embodiment may be omitted. Moreover, in some instances, somefeatures of the present disclosure may be employed without acorresponding use of the other features. Moreover, one or more of theabove-described embodiments and/or variations may be combined in wholeor in part with any one or more of the other above-described embodimentsand/or variations.

Although several exemplary embodiments have been described in detailabove, the embodiments described are exemplary only and are notlimiting, and those skilled in the art will readily appreciate that manyother modifications, changes and/or substitutions are possible in theexemplary embodiments without materially departing from the novelteachings and advantages of the present disclosure. Accordingly, allsuch modifications, changes, and/or substitutions are intended to beincluded within the scope of this disclosure as defined in the followingclaims. In the claims, any means-plus-function clauses are intended tocover the structures described herein as performing the recited functionand not only structural equivalents, but also equivalent structures.Moreover, it is the express intention of the applicant not to invoke 35U.S.C. § 112, paragraph 6 for any limitations of any of the claimsherein, except for those in which the claim expressly uses the word“means” together with an associated function.

The invention claimed is:
 1. An extendable tubular spool comprising: athreaded tube comprising a smooth inner surface and a threaded outersurface with threads having a first orientation; an inner tube, aportion of the exterior surface of the inner tube slidably engageablewithin the smooth inner surface the threaded tube; a tensile tubeengaged with the inner tube, the tensile tube slidably engageable withthe threaded outer surface of the threaded tube; an inner wingcomprising inner threads having the first orientation and outer threadshaving a second orientation, the inner wing configured to threadablyengage with the threaded outer surface of the threaded tube; and anouter wing comprising: a threaded inner surface with threads having thesecond orientation and configured to threadably engage with the outerthreads of the inner wing; and a radially extending mating shoulderconfigured to engage with a corresponding shoulder on the outer surfaceof the tensile tube.
 2. The extendable tubular spool of claim 1, whereinthe first orientation is the opposite of the second orientation.
 3. Theextendable tubular spool of claim 2, wherein the first orientationcomprises left-handed threads and the second orientation comprisesright-handed threads.
 4. The extendable tubular spool of claim 1,wherein the inner wing engages with the tensile tube at a beveled edge.5. The extendable tubular spool of claim 1, wherein the inner tubefurther comprises a first flange, and wherein the threaded tubecomprises a second flange.
 6. The extendable tubular spool of claim 1,wherein the inner tube is configured to threadably engage a first flangeand the threaded tube is configured to threadably engage a secondflange.
 7. The extendable tubular spool of claim 1, wherein the innertube comprises an outer diameter that is substantially similar to aninner diameter of the threaded tube.
 8. The extendable tubular spool ofclaim 1, wherein the inner tube further comprises a wash cone.
 9. Amethod of adjusting the length of an extendable spool, the methodcomprising: unscrewing an outer wing from an inner wing to release atensile tube from a threaded tube, the inner wing threadably engaged tothe threaded tube, and the tensile tube engaged to an inner tube; movingthe tensile tube and the inner tube to a different axial position alongthe length of threaded tube; positioning the inner wing along thethreaded tube to abut the tensile tube; and screwing the outer wing tothe inner wing to secure the tensile tube and the inner tube to thethreaded tube.
 10. The method of claim 9, wherein the step of moving thetensile tube and the inner tube to a different axial position isperformed using a hydraulic cylinder.